4
4-13
Rev.1.0
EIT
4.8 Exception Handling
4.8.2 Address Exception (AE)
[Occurrence condition]
An Address Exception (AE) occurs when access to an unaligned address is attempted in a Load
or Store instruction. The following shows combinatorial instruction and address conditions under
which an Address Exception is invoked.
•
LDH, LDUH, or STH instruction and the two low-order address bits are '01' or '11'
•
LD, ST, LOCK, or UNLOCK instruction and the two low-order address bits are '01,' '10,' or '11'
When an Address Exception occurs, memory access by the instruction that caused the exception
is not performed. Even if an external interrupt is requested when an Address Exception is
detected, the Address Exception is accepted.
[EIT processing]
(1) Saving the SM, IE, and C bits
The PSW Register SM, IE, and C bits are saved to the backup bits-BSM, BIE, and BC.
BSM
←
SM
BIE
←
IE
BC
←
C
(2) Updating the SM, IE, and C bits
The PSW Register SM, IE, and C bits are updated in the manner shown below.
SM
←
Unchanged
IE
←
0
C
←
0
(3) Saving the PC
The PC value of the instruction that caused the Address Exception is set in the BPC
Register. For example, if the instruction that caused the Address Exception is at address
4, then the value 4 is set in the BPC Register; if at address 6, then the value 6 is set in the
BPC Register. In this case, the value of the BPC Register bit 30 indicates whether the
instruction that caused the Address Exception exists on the word boundary (BPC[30] =
0), or not (BPC[30] = 1).
However, in either case of the above, the location to which the RTE instruction returns
after the end of the EIT handler is always address 4. (This is because the two low-order
bits are cleared to '00' when returning to the PC.)
Содержание 32172
Страница 20: ... This is a blank page 16 ...
Страница 21: ...1 1 Overview 1 2 Block Diagram 1 3 Pin Functions 1 4 Pin Layout CHAPTER 1 CHAPTER 1 OVERVIEW ...
Страница 44: ...1 1 24 Rev 1 0 This is a blank page Overview 1 4 Pin Layout ...
Страница 58: ...2 2 14 Rev 1 0 This is a blank page CPU 2 6 Data Formats ...
Страница 122: ...4 4 26 Rev 1 0 This is a blank page EIT 4 13 Precautions on EIT ...
Страница 200: ...7 7 6 Rev 1 0 This is a blank page RESET 7 4 Precautions to Be Taken Immediately after Reset ...
Страница 240: ...8 8 40 Rev 1 0 This is a blank page INPUT OUTPUT PORTS AND PIN FUNCTIONS 8 5 Precautions on Input Output Ports ...
Страница 298: ...9 9 58 Rev 1 0 This is a blank page DMAC 9 4 Precautions on Using DMAC ...
Страница 416: ...10 10 118 Rev 1 0 This is a blank page INPUT OUTPUT TIMERS 10 6 TOM Output Related 16 bit Timers ...
Страница 658: ...14 14 16 Rev 1 0 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 718: ...16 16 16 Rev 1 0 This is a blank page D A CONVERTERS 16 3 Functional Description of the D A Converters ...
Страница 766: ...18 18 22 Rev 1 0 WAIT CONTROLLER 18 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 776: ...19 19 10 Rev 1 0 RAM BACKUP MODE 19 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 777: ...CHAPTER 20 CHAPTER 20 OSCILLATION CIRCUIT 20 1 Oscillator Circuit 20 2 Clock Generator Circuit ...
Страница 782: ...20 20 6 Rev 1 0 OSCILLATION CIRCUIT 20 2 Clock Generator Circuit This is a blank page ...
Страница 856: ...23 23 26 Rev 1 0 This is a blank page ELECTRICAL CHARACTERISTICS 23 6 AC Characteristics ...
Страница 857: ...24 1 A D Conversion Characteristics CHAPTER 24 CHAPTER 24 STANDARD CHARACTERISTICS ...
Страница 859: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 861: ...Appendix 2 1 M32R E Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 865: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...